'Serving' in the Bible

When his division was on duty and he was serving as priest before God,

and was a widow for 84 years. She did not leave the temple complex, serving God night and day with fasting and prayers.

But it must not be like that among you. On the contrary, whoever is greatest among you must become like the youngest, and whoever leads, like the one serving.

For who is greater, the one at the table or the one serving? Isn’t it the one at the table? But I am among you as the One who serves.